Deduplicate and Order Batch and Streaming Logs

Company: Google

Role: Software Engineer

Category: Software Engineering Fundamentals

Difficulty: medium

Interview Round: Onsite

Quick Answer: Reason through deduplicating unsorted logs under both keep-first and keep-latest semantics, then extend the contract to an online stream. Address deterministic ordering, stale state, timestamp ties, late arrivals, memory growth, finality, watermarks, and exactly-once expectations.